Posted 6 May 2009. Crop Management.
University of Illinois at Urbana-Champain. aces.illinois.edu
Urbana-Champain, Illinois (April 16, 2009)--Wet soil and cold conditions to date have caused oat planting to lag behind normal, and consequently, questions have been asked about the impact of delayed planting on the yield of spring oats.
Iowa State University research on date of oat seeding in central Iowa found that after April 15, grain yield drops about 10 percent per week during April and 15 percent per week during the first two weeks of May. They suggest oat yields are best when seeded in late March to mid-April.
Research done by University of Wisconsin at Arlington found when oats where seeded April 18, 29, May 14, and 28, yields were 76.5, 70.6, 62.0, and 46.0 bushels per acre, respectively. Expressed as a percent of maximum yield, the above four dates yielded 100, 92, 81, and 60 percent, respectively.
University of Illinois recommends planting spring oats by April 15 in northern Illinois. A fungicide seed treatment is encouraged. They should not be planted later than May 1, unless being grown as a companion crop for forage establishment.
When drilling oats, a seeding rate of 2 to3 bushels (64 to 96 pounds) per acre or about 30 seeds per square foot is suggested. If broadcasting, the rate needs to be increased by one-half to one bushel per acre. If oats are being planted as a companion crop with alfalfa, seed only 1 to 1.5 bushels per acre.
Oat grain removes 0.38 pound of P2O5 per bushel and 0.20 pound of K2O per bushel. The recommended rate of nitrogen is dependent upon the soil organic matter and the presence of a legume. 50 to 70 pounds of nitrogen per acre are recommended for soil that is 2-3 percent organic matter and where no legume is seeded. If a legume is included with the oats, the nitrogen rate can be reduced by 10 pounds per acre.